The Underwood family was a Quaker family, of Millville, Pennsylvania, and Woodbury, New Jersey. The collection contains chiefly papers of Warner Underwood (1851-1941), Quaker businessman and philanthropist, and his wife, Tamar Eliza John Underwood (1848-1932), including personal correspondence, financial and legal records (1876) relating to a sawmill in Centre County, Pa., student copy work, memorabilia, and historical material relating to Millville.